JP2009166033A - Method for manufacturing catalyst composition of alkali metal halide doped bivalent metal fluoride, and process for preparing fluoroolefin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a catalyst composition expressed by MX/M'F<SB>2</SB>(MX is an alkali metal halide; M is an alkali metal ion selected from a group consisting of Na<SP>+</SP>, K<SP>+</SP>, Rb<SP>+</SP>and Cs<SP>+</SP>; X is a halogen ion selected from a group consisting of F<SP>-</SP>, Cl<SP>-</SP>, Br<SP>-</SP>, and I<SP>-</SP>; M'F<SB>2</SB>is a bivalent fluoride; and M' is a bivalent metal ion). <P>SOLUTION: This method includes; (a) a step that forms an alkali metal halide solution by dissolving an alkali metal halide of some amount in a solvent of amount enough to substantially dissolve or solubilize an alkali metal halide; (b) a step that forms a slurry of the alkali metal halide and bivalent metal fluoride by adding the bivalent metal fluoride of some amount to the alkali metal halide; and (c) a step that forms a solid matter of the alkali metal halide and bivalent metal fluoride by substantially removing the entire solvent from this slurry. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a divalent metal fluoride catalyst composition doped with an alkali metal halide. The invention also relates to a process for producing fluorinated olefins with this catalyst composition.

This application claims priority from US Provisional Patent Application No. 61/012566, filed December 18, 2007, which is incorporated herein by reference.
2,3,3,3-tetrafluoropropene (1234yf), which is a hydrofluoroolefin showing a low global warming potential, is various, such as a refrigerant, a foaming agent, a solvent, a cleaning agent, and a monomer for a polymer compound. Can be used for various purposes.

  One production method for 1234yf involves dehydrochlorination of 1,1,1,2-tetrafluoro-2-chloropropane (244bb). US Provisional Patent Application No. 60/958468, filed July 6, 2007, discloses 1234yf by dehydrochlorinating 244bb in the presence of a divalent metal fluoride catalyst doped with an alkali metal halide. A method of manufacturing is disclosed.

US Provisional Patent Application No. 61/012566 US Provisional Patent Application No. 60/958468

  There is a need for a commercially viable method for preparing divalent metal fluoride catalysts doped with alkali metal halides.

According to the present invention, a method for producing a catalyst composition is provided. The catalyst composition is represented by the formula MX / M′F ₂ where MX is an alkali metal halide and M is selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ^+. Is an alkali metal ion, X is a halogen ion selected from the group consisting of F ⁻ , Cl ⁻ , Br ⁻ and I ⁻ , M′F ₂ is a divalent metal fluoride, and M ′ is It is a divalent metal ion. This method comprises (a) dissolving an amount of an alkali metal halide in an amount of solvent sufficient to substantially dissolve or solubilize the alkali metal halide to form an alkali metal halide solution. (B) adding an amount of divalent metal fluoride to the alkali metal halide solution to form a slurry of alkali metal halide and divalent metal fluoride; and (c) the slurry. Removing substantially all of the solvent from the substrate to form a solid of alkali metal halide and divalent metal fluoride.

  According to the present invention, a method for producing a catalyst composition is provided. The method comprises the steps of: (a) adding an amount of an alkali metal hydroxide, oxide or carbonate to an aqueous solution of hydrogen halide to react to form an aqueous solution of an alkali metal halide; (b) an amount Adding a hydroxide, oxide or carbonate of a divalent metal to an aqueous solution of hydrogen fluoride to react to form a precipitate of a divalent metal fluoride in the aqueous solution; (c) the alkali metal halide Mixing the solution with the divalent metal fluoride precipitate to form an aqueous slurry; and (d) removing water from the aqueous slurry to form a solid.

Still further, according to the present invention, a method for producing a fluorinated olefin is provided. The process has at least one hydrogen and at least one chlorine on adjacent carbons in the presence of a catalytically effective amount of a catalyst composition represented by the formula MX / M′F _2. Dehydrochlorinating the hydrochlorofluorocarbon. MX is an alkali metal halide, M is an alkali metal ion selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ , and X is F ⁻ , Cl ⁻ , Br. ^- and I ^- is a halogen ion selected from the group consisting of, M'F ₂ is a bivalent metal fluoride, M 'is a divalent metal ion.

The catalyst composition, which is a useful product according to the process of the present invention, has the formula:
MX / M'F ₂
Is a blend / mixture of an alkali metal halide (s) and a divalent metal fluoride (s), where MX is an alkali metal halide, and M is , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ are alkali metal ions selected from the group consisting of F ⁻ , Cl ⁻ , Br ⁻ and I ^−. an ion, X is preferably, F ^- and Cl ^- is. M′F ₂ is a divalent metal fluoride, M ′ is a divalent metal ion, and M ′ is preferably Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Ni ²⁺ , Fe ²⁺ , Co Selected from the group consisting of ²⁺ , Cu ²⁺ and Zn ²⁺ , M ′ is most preferably Mg ²⁺ .

Alternatively, the catalyst composition has the formula:
n% MX / M'F ₂
Where n% is the weight percent of the alkali metal halide in the composition, based on the total weight of the composition. The alkali metal halide is preferably from about 0.05% to about 50% by weight of the catalyst composition, more preferably from about 5% to about 15% by weight, based on the total weight of the catalyst composition. %, Most preferably from about 7.5% to about 12.5% by weight.

Examples of alkali metal halides include LiCl, NaCl, KCl, RbCl, CsCl, LiF, NaF, KF, RbF, and CsF. Preferred alkali metal halides include KCl, CsCl, KF and CsF. Examples of divalent metal _{fluorides, MgF 2, CaF 2, SrF} 2, BaF 2, NiF 2, FeF 2, CoF 2, CuF 2 and ZnF ₂ and the like. Preferred divalent metal fluorides include MgF ₂ and NiF ₂ .

  The alkali metal halide is added to a sufficient amount of solvent to substantially dissolve or solubilize the alkali metal halide. Preferred solvents are those that can readily dissolve the alkali metal halide. The choice of solvent can vary depending on the particular alkali metal halide. Examples of solvents that can be used to prepare the catalyst composition of the present invention include water, alcohols, ethers and mixtures thereof. Useful alcohols include monohydric and polyhydric alcohols. The most preferred alcohol is a monohydric alcohol, having 1 to 5 carbon atoms, and the most preferred solvent is water.

  In one embodiment of the method of the present invention, a divalent metal fluoride is added to a solution of an alkali metal halide to form a slurry. After forming the slurry, substantially all of the solvent is removed to form a solid of a mixture of alkali metal halide and divalent metal fluoride. Although the solvent can be removed in one step, a method is preferred in which a part of the solvent is removed from the slurry to form a paste, and then the paste is dried to form a solid. Any conventional technique can be used to remove the solvent. Examples of such techniques include vigorous stirring at room or elevated temperature, evaporation, sedimentation and decantation, centrifugation, and filtration. It is preferred to evaporate the desired amount of solvent to form a paste. The paste is then dried by any suitable method to form a free-flowing, substantially solvent-free powder. Preferred drying methods include oven drying, most preferably performed at a temperature of about 110 ° C. to about 120 ° C., and spray drying. Solvent-free means that the solvent remaining with the powder after solvent removal / drying is less than 1% by weight, preferably less than about 0.5% by weight, more preferably less than about 0.1% by weight, most preferably Means that. Upon removal of the solvent, the powder takes the form of a solid (or powder) of a mixture of alkali metal halide and divalent metal fluoride particles.

  In another embodiment of the method of the invention, a slurry of alkali metal halide and divalent metal fluoride is prepared by different reaction techniques. In the first step, an alkali metal hydroxide, oxide or carbonate is added to and reacted with an aqueous hydrogen halide solution to form an aqueous alkali metal halide solution. In the second step, a divalent metal hydroxide, oxide and carbonate are added to and reacted with an aqueous solution of hydrogen fluoride to form a precipitate of divalent metal fluoride in the aqueous solution. In the third step, the alkali metal halide solution and the divalent metal fluoride precipitate are then mixed to form an aqueous slurry. In the fourth step, the water is then removed from the aqueous slurry by the method described herein to form a solid.

  In some cases, the solid, which is a mixture of an alkali metal halide and a divalent metal fluoride powder, is then fired. Calcination is preferably performed at a temperature of about 100 ° C. to about 750 ° C., more preferably at a temperature of about 200 ° C. to about 600 ° C., and most preferably at a temperature of about 300 ° C. to about 600 ° C. Further, in some cases, the calcination may be performed in the presence of an inert gas such as nitrogen or argon.

  After firing, the powder is optionally further ground to make it more finely divided. This powder is further optionally pelletized to form pellets. This pellet thus provides a catalyst surface for use in applications in actual processes.

  The catalyst composition of the present invention can provide performance advantages over compositions obtained by simple dry mixing of the components. Mixing can be achieved to a more complete degree. The degree of mixing completeness manifests as a higher selectivity of the desired product, such as 1234yf (and less dehydrofluorination product formation, such as 1233xf).

  This catalyst composition is useful for converting hydrochlorofluorocarbons to fluorinated olefins. Useful hydrochlorofluorocarbons have at least one hydrogen and at least one chlorine on adjacent carbons.

  In Table 1, an example of a fluorinated olefin and a precursor hydrochlorofluorocarbon from which a fluorinated olefin can be obtained will be described (the precursor hydrochlorofluorocarbon is shown in the left column, and the corresponding product fluorinated olefin is shown in the right column). ).

  The following are examples of the present invention and should not be construed as limiting.

  In the following examples, 244bb is dehydrochlorinated to 1234yf in the presence of a catalyst that is a blend of an alkali metal halide and a divalent metal fluoride.

Example 1: Various with dehydrohalogenation various CsCl amount of 244bb on CsCl / MgF ₂ catalyst having a CsCl amount, tested a series of CsCl / MgF ₂ catalyst, CsCl added amount of the reaction The effect on sex was measured. Generally, 20 cc of catalyst pellets were used. A mixture of 97.2% / 2.0% 244bb / 1233xf was passed through the catalyst bed at a rate in the range of 470 ° C to 520 ° C at a rate of 6 g / h (grams / hour). The temperature at the bottom and top of the catalyst bed was measured. As shown in Table 2 below, the activity remained almost the same regardless of the amount added, but the selectivity for 1233xf (not the desired dehydrofluoride product) was determined by the amount of CsCl added. It decreased as it increased to 5.0% by weight. On 10 wt% of CsCl / MgF ₂ catalyst, 1233xf was not formed.

Example 2: was tested 10 wt% of alkali metal / in MgF ₂ over a catalyst dehydrohalogenating 10 wt% of 244bb KCl / MgF ₂ and 10 wt% of CsCl / MgF ₂ catalyst chloride. 20 cc of catalyst pellet was used. A 99.1% / 0.4% 244bb / 1233xf mixture was passed through the catalyst bed at a rate of 6 g / h at temperatures ranging from 380 ° C to 480 ° C. The temperature at the bottom and top of the catalyst bed was measured. As shown in Table 3, both catalysts exhibited about the same activity (20%), 10 wt% of CsCl / MgF ₂ catalyst, without producing 1233xf over the catalyst, a higher selection of 1234yf Gave rate.

Example 3: was tested 10% by weight of CsCl / 2-valent metal fluoride catalysts on at dehydrohalogenation 10 wt% of 244bb CsCl / NiF ₂ and 10% by weight of CsCl / MgF ₂ catalyst. 20 cc of catalyst pellet was used. A 99.1% / 0.4% 244bb / 1233xf mixture was passed through the catalyst bed at a rate of 6 g / h at temperatures ranging from 380 ° C to 480 ° C. The temperature at the bottom and top of the catalyst bed was measured. As shown in Table 4, both catalysts are nearly equal, it showed a selectivity of 1234yf (98% to 97%), 10 wt% of CsCl / MgF ₂ catalyst resulted in higher activity.

Example 4: In the dehydrohalogenation Example 4 244bb on MgF ₂ catalyst doped with alkali metal chloride, in order to improve the selectivity of 1234yf, as an additive to MgF _2, a series of The alkali metal chloride was investigated. For comparison purposes, the product obtained on the MgF ₂ catalyst was also reported. In general tests, 20 cc of catalyst pellets were used. A mixture of 97.2% 244bb / 2.0% 1233xf was passed through the catalyst bed at a rate in the range of 470 ° C to 520 ° C at a rate of 6 g / h (grams / hour). The temperature at the bottom of the catalyst bed and at the top of the catalyst bed was measured.

As shown in Table 5, MgF ₂ gives 53-55% 244bb conversion, 80-87% 1234yf selectivity, and 8-15% 1233xf selectivity; 10% LiCl / MgF ₂ gives Gives less than 45% 244bb conversion, about 90% 1234yf selectivity, and about 5% 1233xf selectivity; 10% KCl / MgF ₂ gives less than 50% 244bb conversion, about 96% 1234yf selection And 10% CsCl / MgF ₂ gave 50-52% 244bb conversion, about 97% 1234yf selectivity, and no 1233xf production results. . CsCl showed the best results. The 10% CsCl / MgF ₂ catalyst gave the same activity as MgF ₂ and the highest 1234yf selectivity without producing 1233xf.

  Additional teachings on catalyst compositions having mixtures / formulations of alkali metal halides and divalent metal fluorides and their use in dehydrochlorinating hydrofluorocarbons to fluorinated olefins were published in 2007. No. 60/958468, filed Jul. 6, which is hereby incorporated by reference.

  It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications may be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.

Claims (3)

Formula: MX / M′F ₂
Where MX is an alkali metal halide; M is an alkali metal ion selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ ; X is F ⁻ , Cl ^-, Br ^- and I ^- it is a halogen ion selected from the group consisting of; M'F ₂ is a divalent metal fluoride; and, M 'is represented by a divalent metal ion) A method for producing a catalyst composition, comprising:
(A) dissolving an amount of the alkali metal halide in an amount of a solvent sufficient to substantially dissolve or solubilize the alkali metal halide to form an alkali metal halide solution; ;
(B) adding an amount of the divalent metal fluoride to the alkali metal halide solution to form a slurry of the alkali metal halide and the divalent metal fluoride; and (c) the slurry. Removing substantially all of the solvent from to form a solid of the alkali metal halide and the divalent metal fluoride;
The said manufacturing method containing. A method for producing a catalyst composition, comprising:
(A) adding an amount of alkali metal hydroxide, oxide or carbonate to an aqueous solution of hydrogen halide to react to form an aqueous solution of alkali metal halide;
(B) adding an amount of divalent metal hydroxide, oxide or carbonate to an aqueous solution of hydrogen fluoride to react to form a precipitate of divalent metal fluoride;
(C) mixing the alkali metal halide solution with the divalent metal fluoride precipitate to form an aqueous slurry; and (d) removing water from the aqueous slurry to form a solid. Step;
Including
The alkali metal halide is represented by the formula MX; M is an alkali metal ion selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ ; X is F ⁻ , Cl ^-, Br ^- and I ^- it is a halogen ion selected from the group consisting of; the bivalent metal fluoride is represented by the formula M'F _2; and M 'is a divalent metal ion, the production Method. A method for producing a fluorinated olefin, comprising:
A catalytically effective amount of
Formula: MX / M′F ₂
Where MX is an alkali metal halide; M is an alkali metal ion selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ ; X is F ⁻ , A halogen ion selected from the group consisting of Cl ⁻ , Br ⁻ and I ⁻ ; M′F ₂ is a divalent metal fluoride; and M ′ is a divalent metal ion). A process as described above, comprising dehydrochlorinating a hydrochlorofluorocarbon having at least one hydrogen and at least one chlorine on adjacent carbon in the presence of a catalyst composition.